Results are presented on the discovery of plasma bubble domains (PBD’s), which occur as regular patterns of localized glow discharges formed under ac excitation in an atmospheric pressure inert gas based mixture confined between large-area, closely spaced, plane-parallel, dielectric-covered electrodes. These plasma bubble domains have many characteristics analogous to those of magnetic bubble domains (MBD’s): (1) Changing the applied field changes the size and the shape of the domain that forms (bubble, stripe, etc.). (2) There is a range of applied fields over which a bubble domain exhibits a corresponding range of stable diameters. (3) Bubble domains are bistable. Whereas MBD’s are used in computer memory devices, PBD’s are most likely to be used in computer display devices. ials; electrodes; surface coatings; electric fields; configuration;

Using short (∼ 100 μsec) pulses of rf (1 MHZ) applied to parallel electrodes in air at small electrode spacings (∼ 250 μ) and at an applied field of ∼ 106 V/cm, discharges from both biological and metallic electrodes occurred from a network of points in the electrode surface. These discharges were recorded photographically. Multiple pulses lead to a superposition effect such that a uniform corona exposure appeared on the film. Some effects of electrode material, spacing, and orientation are presented. The results are found to be completely explicable in terms of the ``streamer'' phenomenon of corona discharge. In fact, the wide variety of color effects observed in ``Kirlian'' photography can be accounted for by this mechanism.

We have observed the spatial distribution of coherent or resonance transition radiation (RTR) in the soft-x-ray region of the spectrum (1 -3 keV). Resonance transition radiators were constructed and tested at two accelerators using electron-beam energies ranging from 50 to 228 MeV. These radiators emitted soft x rays in a circularly symmetrical annulus with a half-angle divergence of 2.5-9.0 mrad. The angle of peak emission was found to increase with electron-beam energy, in contrast to the incoherent case, for which the angle of emission varied inversely with electron-beam energy. By careful selection of foil thickness and spacing, one may design radiators whose angle of emission varies over a range of chargedparticle energies. A particular RTR mode (r =m =1) was found to give a sharp annular ring that becomes more accentuated as the number of foils is increased. The RTR effect has application in particle detection, beam diagnostics, x-ray source brightness enhancement, and x-ray free-electron-laser emission.

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The model of the human circulation here used consists of the minimum number of compartments required to simulate the distribution and flow of blood under different conditions. In the model the peripheral circulation consists of four parallel vascular compart ments, each with a typical inflow resistance and compliance. Each of the peripheral compartments is in equilibrium with an interstitial fluid compartment. Blood returning from the peripheral circulation flows into the great veins and pulmonary vessels, from which it is pumped by the heart into the high-pressure aorta and arteries. The distribution and flow of blood are regulated by the autonomic nervous system, which receives inputs from arterial pressure and pulmonary blood volume, and which controls cardiac output and the resistance and compliance of each peripheral vascular compartment.